Telephone-transmitter.



81 C. PORTER. TELEPHONE TRANSMITTER. APPLICATION FILED JUNE 12. 1915.

1,171,460. Patented Feb. 15,1916.

I. VIIIIIII'III III IIIIII'I'I I 5 l I I 9 I I i 1 r Attest: Inventor:

3 72 MTWQMWM 7 Atty STEPHEN C. PORTER, OF NEW YORK, N. Y.

TELEPHONE-TRANSMITTER.

Application filed June 12, 1915. Serial Not 33,707.

To all whom it may concern:

Be it known that I, STEPHEN C. PORTER, a citizen of the United States, residing at the borough of Brooklyn, New York city, in the county of Kings and State of New York, have invented certain new and useful Improvements in Telephone-Transmitters, of which the following is a specification.

My invention relates to sound intensifiers for sensitivetelephone transmitters and my objects are the production of a simple, cheap and highly efficient device, which vastly increases the sensitiveness of the transmitter and enables it to pick up sounds emanating at a distance.

The drawing is a sectional, perspective View of one form of my invention.

A sensitive telephone transmitter a is mounted with its diaphragm facing and spaced from the back 1 of resonator 1), whose front is open to the passage of sound waves. This first resonator b may then be mounted in a second resonator c with its front 2, also open to the passage of sound waves, facing and spaced from the back 3 of the resonator c. The open front 4 of the resonator c faces the general direction from which the sound originates. This open front may be concealed by a screen 5 of any suitable material which does not impede the free passage ofsound waves and the opening may be either the full extent of the front or any desired lesser opening.

Excellent results may be secured by using one resonator b but experiment has shown that two arranged as shown in the drawing will greatly increase the sensitiveness and power of the transmitter.

I claim 1 The combination of a resonator whose front is open to the passage of sound waves and whose back is substantially flat throughout and a sensitive telephone transmitter mounted therein facing the back thereof with its diaphragm only slightly separated therefrom.

2. The combination of a resonator whose front is open to the passage of sound waves, a sensitive telephone transmitter therein facing the back of the resonator with its diaphragm slightly separated therefrom and a second resonator with a like front outside the first with its open front opposed to and slightly separated from the back of the first resonator. I I

In testimony whereof I have aflixed mysignature in presence of two witnesses.

I STEPHEN G. PORTER.

Witnesses:

ROBERT E. KILLGORE. MAY M. LIPP. 

